Briquette of ferrous metal working scrap, method of making the same, mashing crusher of grinding chips and briquette making apparatus using the same

ABSTRACT

A briquette meeting required strength that is formed in an energy-saving manner from ferrous metal working scrap, such as grinding chips, and a method of making the briquette are provided. In a briquette formed by applying a pressing pressure to a ferrous metal working scrap, the percentage by weight of grinding chips is in the range of 10 wt % to 35 wt %. Viscous water-containing grinding chips crushed to a desired size and metal working scrap, such as gear cutting chips, are mixed in a feed hopper  7,  and a pressing pressure is then applied to the raw mix by use of a compression pressing machine  8  to form a briquette B of ferrous metal working scrap. The content of a grinding fluid of the viscous water-containing grinding chips is 20 wt % to 60 wt %.

TECHNICAL FIELD

The present invention relates to a briquette made from metal workingscrap discharged as a result of grinding and the like for the purpose ofrecycling as a material used in blast furnaces, a method of making thebriquette, a mashing crusher of grinding chips for the making of thebriquette, and a briquette making apparatus using the mashing crusher.

BACKGROUND ART

Conventionally, grinding chips resulting from grinding become spongybodies that contain a grinding fluid, such as grinding water andgrinding oil used during grinding, and after dried in a machining plant,the spongy bodies, are incinerated in an incineration furnace, disposedby landfill for value, or used as a reducing agent for blast furnaces ina steelworks.

For grinding chips containing about 70% of ferrous metals, for example,as described in the Japanese Patent Laid-Open No. 56-23237, a treatmentmethod of briquetting is known so that such grinding chips are reused asa raw material in blast furnaces of a steelworks. In this method,grinding chips, turning chips and metal powders for compositionadjustment are blended and heated in a primary heating furnace to removemoisture, oil and the like, whereby a preliminary briquette is made, andafter that, briquetting is performed by secondary heating in ahigh-temperature secondary heating furnace.

Furthermore, as described in the Japanese Patent Laid-Open No.2002-241854, there is known a method of making a briquette by whichgrinding chips resulting from grinding are naturally dried to reduce thecontent of a grinding fluid to not more than 20 wt %, shot wasteresulting from shot blasting and gear cutting chips resulting from gearcutting, the oil content of which is reduced to not more than 6 wt %,are added to these grinding chips, the blending ratio of these materialsis adjusted to 2 (grinding chips): 1 (shot waste): 7 (gear cuttingchips), and a pressing pressure is applied after mixing and string.

However, in the method described in the Japanese Patent Laid Open No.56-23237, equipment and devices such as a large heating furnace must beprovided on a large scale and besides the treatment requires a largequantity of energy, posing the problem that the effect of recyclingresources decreases by half.

The briquette making method described in the Japanese Patent Laid-OpenNo. 2002-241854, which involves mixing shot waste, has the problem thatduring the extrusion of moisture by applying a pressing force, shotwaste becomes a hindrance and that in some ways of mixing, shot wasteinduces a decrease in shatter strength and variations in requiredstrength after briquetting, thereby causing cracks.

The present invention was made in view of these problems in conventionaltechniques and has as its object the provision of a briquette meetingrequired strength that is formed in an energy-saving manner from ferrousmetal machining scrap, such as grinding chips, a method of making thebriquette, a mashing crusher of grinding chips capable of reducing theenergy consumed in briquetting in order to effectively reuse grindingchips, and a briquette making apparatus that uses the mashing crusher.

DISCLOSURE OF THE INVENTION

To solve the above-described problems, a briquette is formed by applyinga pressing pressure to ferrous metal working scrap, in which thepercentage by weight of grinding chips is 10 wt % to 35 wt %.

According to one aspect of the invention, the briquette of ferrous metalworking scrap contains any one of turning chips, gear cutting chips andpress scrap as a component other than the grinding chips.

The invention also includes a method of making a briquette of ferrousmetal working scrap, which comprises the steps of: mixing viscouswater-containing grinding chips crushed to a desired size and metalworking scrap, such as gear cutting chips, and applying a pressingpressure to the material mix to form a briquette of ferrous metalworking scrap.

According to another aspect of the invention, in the method of making abriquette of ferrous metal working scrap, the content of a grindingfluid of the water-containing grinding chips is not less that 20 wt %but not more that 60 wt %.

The invention further includes a mashing crusher that crushes grindingchips solidified in a dried condition to a desired size, which comprisesa plurality of cylindrical biting-in bars, a plurality of partitionplates arranged above the biting-in bars, an outer frame member thatfixes the plurality of biting-in bars and partition plates at prescribedintervals, meshed metal members provided in a prescribed arrangement atprescribed intervals from the biting-in bars fixed to the outer framemember, and reciprocal driving means that causes the outer frame memberto move reciprocally on the meshed metal members, and crushes solidifiedgrinding chips supplied to within the outer frame member to a desiredsize by causing the outer frame member to move reciprocally on themeshed metal members.

The invention further includes a mashing crusher that crushes grindingchips solidified in a water-containing condition to a desired size,which comprises a plurality of cylindrical biting-in bars, a pluralityof partition plates arranged above the biting-in bars, an outer framemember that fixes the plurality of biting-in bars and partition platesat prescribed intervals, meshed metal members provided in a prescribedarrangement at prescribed intervals from the biting-in bars fixed to theouter frame member, and reciprocal driving means that causes the outerframe member to move reciprocally on the meshed metal members, andcrushes solidified grinding chips supplied to within the outer framemember to a desired size by causing the outer frame member to movereciprocally on the meshed metal members.

According to another aspect of the invention, by use of a screw-conveyorcrusher that comprises a screw conveyor for grinding chip supply that isprovided in the vicinity of the crushing arms, the maxing crusher ofgrinding chips crushes the solidified grinding chips to an appropriatesize and then supplies the crushed solidified grinding chips to withinthe outer frame member.

The invention further includes a briquette making apparatus thatcomprises the mashing crusher of grinding chips and the screw conveyorthat supplies turning chips and/or gear cutting chips, and performs asynchronized operation of the screw conveyor for grinding chip supplyand the screw conveyor that supplies the turning chips and/or gearcutting chips, thereby causing the grinding chips and the turning chipsand/or gear cutting chips to fall onto the transfer conveyor of thecompression pressing machine at a desired blending ratio.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side view of a briquette making apparatus;

FIG. 2 is a schematic top view of a briquette making apparatus;

FIG. 3 is a side view of a screw conveyor crusher;

FIG. 4 is a front view of a holding plate;

FIG. 5 is a schematic front view of a mashing crusher;

FIG. 6 is a schematic side view of a mashing crusher;

FIG. 7 is a drawing to explain the operation of a briquette makingapparatus;

FIG. 8 is a drawing that shows the relationship between the blendingratio of grinding chips and gear cutting chips and shatter strength; and

FIG. 9 is a perspective view of a briquette.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the invention will be described below on the basis of theaccompanying drawings, in which FIG. 1 is a side view of a briquettemaking apparatus, FIG. 2 is a top view of the same, FIG. 3 is a sideview of a screw conveyor crusher, FIG. 4 is a front view of a holdingplate, FIG. 5 is a schematic front view of a mashing crusher, FIG. 6 isa schematic side view of the same, FIG. 7 is a drawing to explain theoperation of a briquette making apparatus, FIG. 8 is a drawing thatshows the relationship between the blending ratio of grinding chips andgear cutting chips and shatter strength, and FIG. 9 is a perspectiveview of a briquette.

A briquette of ferrous metal working scrap according to the invention isformed in a blending ratio of grinding chips between 10 and 35 wt % togear cutting chips between 90 and 65 wt %. In addition to the gearcutting chips, any one of turning chips and press scrap may be used as acomponent to be blended with the grinding chips.

Gear cutting chips refer to metal scrap resulting from the working byuse of a hobbing machine and a gear shaper and are ferrous granularchips of 1 to 4 mm or so. Gear cutting chips are mixed after the oilcontent is removed to not more than 6 wt % by use of a centrifugalseparator. In recent years, however, gear cutting has been performed ina dry state and performing gear cutting without using a cutting oil hasbecome mainstream.

Turning chips are metal scrap resulting from lathing and working by useof a drilling machine, a milling machine, etc. and refer to helical orgently linear continuous chips. Incidentally, if turning chips are in asomewhat long state, this may sometimes cause a hindrance duringtransfer and, therefore, it is desirable to cut or crush such longturning chips to a desired length before use.

Next as shown in FIGS. 1 and 2, a briquette making apparatus accordingto the invention comprises a grinding chip hopper 1, a screw-conveyorcrusher 2 that crushes solidified grinding chips supplied from thegrinding chip hopper 1 to a certain size, a mashing crusher 3 thatfurther crushes the grinding chips carried in from the screw conveyorcrusher 2 to a desired size, a gear cutting chip hopper 4, a screwconveyor 5 that transfers gear cutting chips supplied from the gearcutting chip hopper 4, a transfer conveyor 6 that transfers the grindingchips crushed by the mashing crusher 3 and the gear cutting chipstransferred by the screw conveyor 5 while blending them, a supply hopper7 that stores the raw mix of grinding chips and gear cutting chipstransferred by the transfer conveyor 6, and a compression pressingmachine 8 that makes a briquette B by pressing the raw mix supplied fromthe supply hopper 7.

Incidentally, the reference numeral 9 denotes a motor that drives thescrew-conveyor crusher 2, the reference numeral 10 a motor that drivesthe screw conveyor 5, the reference numeral 11 a control panel, and thereference numeral 12 an infrared sensor that detects the storage volumeto prevent an overflow from the supply hopper 7.

As shown in FIG. 3, the screw-conveyor crusher 2 is disposed within aguide member 21 in communication with the grinding chip hopper 1 andcomprises a screw conveyor 24 that is provided, at the leading endthereof, with key-like crushing arms 22 and, on the peripheral surfacethereof, with a conveyor fin 23, and a holding plate 25 that isinstalled fixedly in the guide member 21 in the vicinity of the crushingarms 22.

The guide member 21 is formed so as to cover the screw conveyor 24, withan inlet 21 a that receives the solidified grinding chips supplied fromthe grinding chip hopper 1 formed on a top surface thereof and an outlet21 b that delivers the solidified grinding chips to the mashing crusher3 after being crushed to a certain size formed on a bottom surfacethereof in the vicinity of the crushing arms 22.

As shown in FIG. 4, the holding plate 25 is formed in circular are formalong the periphery of the screw conveyor 24 provided, on the peripheralsurface thereof, with the conveyor fin 23, so as to form a prescribedgasp from the conveyor fin 23. Incidentally, the reference numeral 26denotes a guide plate that guides grinding chips to between the screwconveyor 24 end the holding plate 25, and the reference numeral 27denotes a bolt that fixes the holding plate 25 to the guide member 21.

As shown in FIGS. 5 and 6, the mashing crusher 3 comprises an outerframe member 31 having open top and bottom surfaces, a plurality ofcylindrical biting-in bars 32 fixed at prescribed intervals to lowerright and left inner wall surfaces of the outer frame member 31, aplurality of partition plates 33 that are arranged above these biting-inbars 32 and fixed to right and left inner wall surfaces of the outerframe member 31, meshed metal members 34 provided in a prescribedarrangement at prescribed intervals from the biting-in bars 32, andreciprocal driving means 35 that causes the outer frame member 31 tomove reciprocally in the directions of arrow A on the meshed metalmembers 34. Incidentally, it is preferred that the partition plates 33be arranged in the middle of the pitch of the biting-in bars 32, asshown in FIG. 7.

The reciprocal driving means 35 comprises four cam followers 36 providedon front and rear, right and left outer wall surfaces of the outer framemember 31, four guide rails 37 laid on a tame body (not shown) so as tosandwich these cam followers 36, a connecting rod 39 an end of which isconnected to an outer wall surface of the outer frame member 31 and theother end of which is connected to an edge of a crank part 38, and amotor 40 that rotates the crank part 38.

The operation of the briquette making apparatus constructed as describedabove and a method of making a briquette will be described below.

First, viscous water-containing grinding chips discharged in grindingare accumulated and collected by a dedicated car or the lie and put intothe grinding chip hopper 1. The collected grinding chips are spongybodies that contain a grinding fluid, such as grinding water andgrinding oil, in an amount of not less than 20 wt % but not more than 60wt %.

On the other hand, gear cutting chips resulting from gear cutting arecollected and put into the gear cutting chip hopper 4. When a grindingoil is use, the oil content is lowered to not more than 6 wt % by use ofa centrifugal separator. On this occasion, the size of the gear cuttingchips is 1 to 4 mm or so.

When the viscous grinding chips in a water-containing condition that aresupplied from the grinding chip hopper 1 are delivered to thescrew-conveyor hopper 2, the screw conveyor 24 is rotationally driven bythe motor 9 to transfer the grinding chips toward the outlet 21 b. Then,the grinding chips solidified in a water-containing condition enter thegap between the screw conveyor 24 and the holding plate 25 by the actionof the guide plate 26 and the holding plate 25 and are crushed to acertain size by the crushing arms 22 that rotate together with the screwconveyor 24.

As shown in FIG. 7, the grinding chips W1 crushed to a certain size areput within the outer frame member 31 of the mashing crusher 3. Then, bythe reciprocal movement of the outer frame member 31 provided with theplurality of biting-in bars 32 and partition plates 33 on the meshedmetal members 34, each of the biting-in bars 32 pushes the grindingchips W1 against the meshed metal members 34. And, the grinding chips W1pass through the meshed metal members 34, are crushed to sizes smallerthan the size of the network at least and fall onto the transferconveyor 6.

It became apparent that the size of the grinding chips W1 during mixingwith gear cutting chips W2 on the supply conveyor 7 has an effect on thestrength of a briquette B. In order to increase the strength of thebriquette B, it is desirable to chips the grinding chips W1 to smallersizes and to uniformly disperse the grinding chips W1 within thebriquette B. Furthermore, even when the percentage by weight of thegrinding chips W1 is lowered, because of the viscosity of the grindingchips W1 that have passed trough the metal members 34, in some sizes thegrinding chips W1 may adhere to each other and be contained as largeagglomerates within the briquette B, with the result that these partsinitiate cracks.

Therefore, it is preferred that the size of the grinding chips W1 thathave passed through the meshed metal members 34 be not more than 20 mmin diameter so that the grinding chips 1 are uniformly dispersed withinthe briquette B to increase strength. The size of the grinding chips W1that are put into the supply hopper 7 can be arbitrarily set byappropriately selecting the size of the meshes of the metal members 34.

On the other hand, the gear cutting chips W2 supplied from the gearcutting chip hopper 4 are transferred by the screw conveyor 5 and fallonto the transfer conveyor 6.

Then, the grinding chips W1 and the gear cutting chips W2 are blended onthe transfer conveyor 6, transferred in the direction of the arrow C andput into the supply hopper 7 that stores the raw mix of the grindingchips W1 and the gear cutting chips W2.

The blending ratio of the grinding chips W1 and the gear cutting chipsW2 can be arbitrarily set by controlling the number of revolutions ofthe motor 9 that drives the screw conveyor 24 and the number ofrevolutions of the motor 10 that drives the screw conveyor 5 thereby toadjust the amount of the grinding chips W1 transferred to the mashingcrusher 3 and the amount of the gear cutting chips W2 transferred to thetransfer conveyor 6.

That is, it is necessary only that synchronized operation of the motor 9and the motor 10 be performed in consideration of the amount of the gridchips W1 transferred per revolution for the screw conveyor 24 and theamount of the gear cutting chips W2 transferred per revolution for thescrew conveyor 5.

Subsequently, the grinding chips W1 and the gear cutting chips W2 aremixed in the supply hopper 7 and supplied to the compression pressingmachine 8. When the raw mix is compressed by the compression pressingmachine 8, the grinding fluid of the water-containing grinding chips isdischarged in the direction in which the pressure is applied and adirection opposite to this direction On that occasion, the grindingfluid runs through the gear cutting chips that become aggregates anddischarge onto the wall surfaces of press dies (not shown).

And, after a constant pressing pressure is held for a prescribed time, apiston (not shown) opens a pressure receiving door (not shown) andpushes the briquette B to outside the press dies. Furthermore, when thepiston has moved forward to the end of the pressure receiving door, theoil, moisture and the like add to the wall surfaces of the press diesrun through a drain groove (not shown) and are discharged downward.

Then, the formed briquette B is delivered and housed on a truck 13.

Even when the briquette B made in the above described method is causedto fall from a height of 2 m, cracks or fissures dot not occur andrequired strength is satisfied. As shown in FIG. 8, in the case of thebriquette B formed by blending grinding chips and gear cutting chips, itis apparent that required shutter strength (specified height: not lessthan 2 m) can be satisfied by keeping the amount of grinding chips atnot more than about 35 wt %.

In the briquette B of ferrous metal working chips according to theinvention, forming was performed without mixing shot scrap. This isbecause it became apparent that in a case where shot scrap is mixed withgrinding chips etc., if shot waste is unevenly dispersed and the greaterpar of the shot waste is present only at one side in some ways ofmixing, cracks occur, resulting in a decrease in the shatter so of thebriquette and variations in required strength.

As shown in FIG. 9, cracks occur when the briquette is made of 20 wt %of cutting chips, 70 wt % of gear cutting chips and 10 wt % of shotwaste. That is, a decrease in shatter strength is induced by mixing 10 %of shot waste even when the amount of cutting chips is not more than 35wt %.

On the other hand, cracks do not occur in a case where the briquette ismade of 30 wt % of grinding chips and 70 wt % of gear cutting chips.This is apparent also from the relationship between the blending ratioof grinding chips and gear cutting chips and shatter strength shown inFIG. 8. When the amount of grinding chips is 100 wt %, cracks occur asis apparent from the shatter strength shown in FIG. 8.

Incidentally, in this embodiment, descriptions were given of a briquettein which gear cutting chips are blended to grinding chips, a method ofmaking the briquette, and a briquette making apparatus. However, inplace of gear cutting chips, other metal working scrap, such as tuningchips and press scrap, can be used. In this case, it is necessary onlythat a briquette making apparatus be constructed by replacing the gearcutting chip hopper 4 with a turning chip hopper and replacing the screwconveyor 5 that transfers gear cutting chips with a screw conveyor thattransfers turning chips.

Also, it is possible to blend both turning chips and gear cutting chipswith grinding chips at a desired blending ratio. In this case it ispossible to construct a briquette making at by providing a gear cuttingchip hopper and a new screw conveyor that transfers gear cutting chipsor it is possible to construct a briquette making apparatus in such amanner that turning chips and gear cutting chips are put into the gearcutting chip hopper 4 in a mixed manner and the raw mix of turning chipsand gear cutting chips is supplied from the screw conveyor 5 to thetransfer conveyor 6.

Incidentally, in general, the solidified grinding chips to be crushed bythe mashing crusher according to the invention are solidified, withmoisture contained in the interior even when the surface is dry.

INDUSTRIAL APPLICABILITY

As described above, a briquette is formed from ferrous metal workingscrap, such as grinding chips, in an energy-saving manner and thebriquette can meet required strength.

Further, a briquette can be formed from ferrous metal working scrap,such as viscous water-containing grinding chips, without natural dryingin an energy-saving manner and costs can be reduced.

Also, grinding chips that are solidified in a dried condition can becrushed to a desired size by use of a simple mechanism.

Also, grinding chips that are solidified in a water-containing conditioncan be crushed to a desired size by use of a simple mechanism.

Further, solidified grinding strips can be smoothly crushed to a desiredsize by causing the solidified grinding chips to pass through ascrew-conveyor crusher and a mashing crusher.

The energy consumed in briquetting can be saved in order to effectivelyreuse grinding chips.

1. A briquette making apparatus comprising: a mashing crusher thatcrushes grinding chips solidified in a dried condition to a desiredsize, wherein the mashing crusher comprises: a plurality of cylindricalbiting-in bars, a plurality of partition plates arranged above thebiting-in bars, an outer frame member that fixes said plurality ofbiting-in bars and partition plates at prescribed intervals, meshedmetal members provided in a prescribed arrangement at prescribedintervals from said biting-in bars fixed to the outer frame member, andreciprocal driving means that causes said outer frame member to movereciprocally on the meshed metal members, and crushes solidifiedgrinding chips supplied to within said outer frame member to a desiredsize by causing said outer frame member to move reciprocally on saidmeshed metal members; and, a screw conveyor-crusher that suppliesgrinding chips to said mashing crusher, said screw conveyor-crushercomprising a first screw conveyor that is provided at a leading endthereof with crushing arms and a holding plate, said holding plate beingprovided in the vicinity of said crushing arms, the screw-conveyorcrusher crushes solidified grinding chips to an appropriate size andthen supplies the crushed solidified grinding chips to within said outerframe member of the mashing crusher; wherein said briquette makingapparatus performs a synchronized operation of said first screw conveyorfor grinding chip supply and a second screw conveyor that supplies atleast one of turning chips and gear cutting chips, thereby causing thegrinding chips and the at least one of the turning chips and the gearcutting chips to fall onto a transfer conveyor of a compression pressingmachine at a desired blending ratio, and wherein said desired blendingratio is a ratio between the grinding chips and the at least one of theturning chips and the gear cutting chips.
 2. A briquette makingapparatus comprising: a mashing crusher that crushes grinding chipssolidified in a water-containing condition to a desired size, whereinthe mashing crusher comprises: a plurality of cylindrical biting-inbars, a plurality of partition plates arranged above the biting-in bars,an outer frame member that fixes said plurality of biting-in bars andpartition plates at prescribed intervals, meshed metal members providedin a prescribed arrangement at prescribed intervals from said biting-inbars fixed to the outer frame member, and reciprocal driving means thatcauses said outer frame member to move reciprocally on the meshed metalmembers, and crushes solidified grinding chips supplied to within saidouter frame member to a desired size by causing said outer frame memberto move reciprocally on said meshed metal members; and, a screwconveyor-crusher, which supplies grinding chips to said mashing crusher,said screw conveyor-crusher comprising a first screw conveyor that isprovided at a leading end thereof with crushing arms and a holdingplate, said holding plate being provided in the vicinity of saidcrushing arms, screw conveyor-crusher crushes said solidified grindingchips to an appropriate size and then supplies the crushed solidifiedgrinding chips to within said outer frame member of said mashingcrusher; wherein said briquette making apparatus performs a synchronizedoperation of said first screw conveyor for grinding chip supply and asecond screw conveyor that supplies at least one of turning chips andgear cutting chips, thereby causing the grinding chips and the at leastone of the turning chips and the gear cutting chips to fall onto atransfer conveyor of a compression pressing machine at a desiredblending ratio, and wherein said desired blending ratio is a ratiobetween the grinding chips and the at least one of the turning chips andthe gear cutting chips.